Pathophysiology of reactions associated with pertussis vaccine.

Many adverse clinical events occur after pertussis immunization in children, but the pathophysiology is not well understood. It has been suggested that some of these adverse events may be due to biologically-active LPF and endotoxin present in DTP vaccines. Fifty-six children were studied who experienced severe reactions (fever greater than or equal to 40.5 degrees C, seizures, persistent crying greater than or equal to 3 hours or hypotonic-hyporesponsive episodes) within 48 hr of DTP immunization. Leukocytosis with neutrophilia was noted acutely (after vaccination) compared to follow-up (approximately one month later). No changes in insulin or glucose values were noted. Utilizing the CHO cell assay, no biologically-active LPF was found in the acute sera of children who had DTP-associated seizures. We found no evidence that biologically-active LPF or altered insulin/glucose metabolism were related to severe DTP-associated reactions.